06 inconsistent starting when warm / hot
  • User avatar
    metal_jd
    Posts: 5
    Joined: Thu Aug 09, 2018 4:33 pm

    06 inconsistent starting when warm / hot

    by metal_jd » Sat Sep 29, 2018 2:23 pm

    Hello I have used the search function but do not really see my symptoms , hopefully i can get some guidance. I have a new to me 06 250r. When I bought it started and ran and rode fine, the next day when I went to ride for the day it would not start.I kicked and kicked. Through the forum here and with a manual I tested the electrical system, and then I completely removed the carb from the bike (have pics to prove it lol ) and disassembled and found a clogged jet. Continued the cleaning and inspection and reassembled it. It started on the 2nd choked kick, and I adjusted the Idle down.
    I have briefly rode it a couple of time and it seems like it runs fine with plenty of power, good throttle response and I can even lug it a little when needed. But it has this issue where it is very inconstant starting back up after its warm and or hot. I have a 170 main , a 42 Slow , My needle is 3 from the top, and ( I may have wrote this down wrong) a NHGT on the needle, pilot 1 3/4 out. Also It seems like the idle gets higher while riding it. I am baffled as to why it can start 45 mins hot using the hot start, but then not start at all the next time out same situation or even warm.

    Keyword here would be inconsistent warm / hot when its cold it fires right up choked and runs great... Thankful for any input...
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: 06 inconsistent starting when warm / hot

    by JimDirt » Sat Sep 29, 2018 3:40 pm

    Welcome to the site !! \:D/

    What elevation are you at ?? , this will to help diagnose the issue , in reference to your jetting

    Also , your jetting sounds good (depending on your elevation) , with the exception of the needle , it "should " be a NHFS , I do not even see a NHGT listed for that bike from 04-12 in the Factory Honda Service Manual , so that is the only thing not "stock" setting , as far as other possibilities if you did not replace the jet and only cleaned it , its possible it is still partially clogged , if the idle is fine , then raises , then maybe the next time is low , it could be the Needle Jet is worn/ovaled (the Needle Jet is the long tube your Main Jet screws into and goes up into the venturi) , that would also account for a inconsistent idle , as could the Floating Plate seal , on the slide (the removable plate) , it also has to be on in a certain direction with the hole at the bottom of the plate , and may contribute to your starting issue , as it may richen or lean the mixture depending on if its rattling around enough

    Did you remove/check the actual function of the Hot Start Plunger ?? , if the jets were clogged , its possible the plunger has a green coating on it , if it does , it could be sticking in the tube , which would either richen or lean the mixture depending , you should have noticed this when you took the carb apart to clean it , if the plunger has slime on it , then clean it with cleaner and/or wipe it down with a fine steel wool pad

    Also , you did not mention if you checked the valves or not , if the intakes are zeroing out , it will have issues with starting , idling , and even running eventually , depending on if they are close or or at 0 , so there are plenty of variables here to possibly be the issue , knowing your elevation will help along with weather you cleaned or replaced the pilot jet

    Our resident Carb Guru , is Leardriver , he might be able to shed more light on your inconsistent starting , so hopefully he will chime in as well , if its a fuel related issue , he is the guy ...
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: 06 inconsistent starting when warm / hot

    by Back2-2 » Sat Sep 29, 2018 4:19 pm

    The first thing that I see in your statement is the use of the - "start 45 mins hot using the hot start, but then not start at all the next time out same situation or even warm." The Hot start is not for starting the engine while it's hot. It is for starting the engine hot after a crash which gives you a flooded condition. It should be called a flooded start or lean start lever but it's not. So you my be just using that "Hot Start" in the incorrect conditions and trying to start the bike lean which makes it difficult. It leans the mixture from a flooded condition. Your jetting appears to be fine unless you live at some extreme altitude.

    If I misinterpreted your comments, my regards.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • User avatar
    metal_jd
    Posts: 5
    Joined: Thu Aug 09, 2018 4:33 pm

    Re: 06 inconsistent starting when warm / hot

    by metal_jd » Sat Sep 29, 2018 7:40 pm

    So I am at Sea level, I did pull both the choke and hot start plungers and cleaned them to a copper color. I did not replace any jets or the needle. I will pull the needle and check it again for the wear that you are saying and to confirm the letters on it. I will also check the plate seal. I also have not checked the valves but will do that also.

    The hot start lever is baffling to me as to the starting of this bike. This is my first newer 4 stroke so I would forget about it. Kick kick kick to no start, then remember pull the hot start and it would fire up. Then another time I would remember to initially pull it and it wont start.

    Perhaps the valve check and a throttle valve seal can lead me to some more narrowing of the issue.. Thank you for the input guys!
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: 06 inconsistent starting when warm / hot

    by Back2-2 » Sat Sep 29, 2018 8:48 pm

    Just remember the hot lever is something you will hardly ever use. It leans the fuel mixture by inducing air the the circuit. If you dump it a lot and the bike does not restart that is when you use the hot start.
    Also - when you kick a 4 stroke over you do not give it a jab like a 2 stroke. You find TDC then give it a full weight kick ALL the way through the stroke. Do not give it throttle as many do with 2 strokes either. Keep your hand off the throttle to make sure you are not accidentally twisting while kicking it over.

    I do not concur with the needle wear being your issue. If the floating valve seal is bad it is going to run bad all the time.
    You may need to look for air leaks in the crab manifolds. That can cause idle to go up and down as you described and also cause starting issues.

    When it does start for you it runs fine correct ?
    Last edited by Back2-2 on Sun Sep 30, 2018 4:50 am, edited 1 time in total.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: 06 inconsistent starting when warm / hot

    by JimDirt » Sat Sep 29, 2018 9:03 pm

    Just as a notation Neil , a worn Needle Jet , does give a inconsistent idle as described , as the needle is bouncing around in a worn needle jet , the idle can be low or normal , then the next time be high to where you have to adjust the idle , then the next time it will die because its too low because you lowered it when it was high , i have actually had it happen to me twice , and the needle jet both times was the issue , the second time the needle itself was worn as well , so i replaced both , so this is why i brought it up , it wont necessarily cause it to run bad , though it may surge once in a while , but usually it will just idle inconsistently .... ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: 06 inconsistent starting when warm / hot

    by Back2-2 » Sun Sep 30, 2018 4:56 am

    I guess if he wants to give it a $15-$20 shot what the heck. A worn slide can also cause inconstant idle and throttle response and that can also be a $25 shot in the dark. It could also be a accelerator pump issue but that also would be a $25 shot in the dark.

    Basic simple things first for those conditions he is describing.
    1. Proper starting procedure.
    2. Not using the Hot start.
    3. A/F screw condition and proper install.
    4. Jetting.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • User avatar
    metal_jd
    Posts: 5
    Joined: Thu Aug 09, 2018 4:33 pm

    Re: 06 inconsistent starting when warm / hot

    by metal_jd » Sun Sep 30, 2018 8:05 am

    Yes once running it runs great IMO, with the exception of the idle basically creeping up my slow speeds. I also have become very conscious of the starting procedure since having so much trouble with this now. I am gonna try to replace the needle and see where that gets me. Once done Ill post some results. thank you both again
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: 06 inconsistent starting when warm / hot

    by Back2-2 » Sun Sep 30, 2018 8:17 am

    By "creeping up" your slow speeds - does that mean the idle is increasing ? That usually relates to air leak and or throttle cable / slide control.
    One other thing comes to mind - I have found this many times on street bikes and tend to overlook it on dirt bikes.
    Check your vent tubes on the carb. If there is any blockage that can really cause issues that are tough to find. Everything from unstable and inconsistent idle to stalling after short runs ect...

    Just for info. - The needle is not part of the starting or idle circuit. It only comes into effect as you open the throttle through approx. mid throttle. That is the taper designed into it giving you the linear fueling.

    One other thing just came to mind. Maybe just to see the results - disconnect the TPS and give it a go. Easy to unplug it.
    Many people remove the TPS completely on FCR carbs and find better throttle response.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: 06 inconsistent starting when warm / hot

    by JimDirt » Sun Sep 30, 2018 12:10 pm

    Just for info. - The needle is not part of the starting or idle circuit. It only comes into effect as you open the throttle through approx. mid throttle. That is the taper designed into it giving you the linear fueling.
    just for info/info .. :mrgreen: , The needle becomes part of the idle circuit when the Needle Jet is worn and allows fuel to enter the system via the ovaled out Needle Jet orifice , which then accounts for the idle going up/down due to the fuel getting by what would otherwise be a "metered" circuit , it now becomes a randomly open circuit , hence the idle inconsistency and why sometimes its high and sometimes its idling normally ..... , not saying this is always the case , just saying it does happen when the Needle Jet is compromised and worn , which allows fuel to bypass intermittently when the throttle is closed , when the throttle is open , then the wear has no effect on the metering of the fuel circuit ;) ...make sense ??
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Aussiecrf230
    Posts: 1964
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: 06 inconsistent starting when warm / hot

    by Aussiecrf230 » Sun Sep 30, 2018 3:44 pm

    The trouble for Metal_jd is both Jim and Neil are both right, though have identified different causes.

    Metal_jd just work your way through the suggestions till you find the cause.
    You will find a lot of knowledge and experience on the forum and we all like to put forward our 2 cents worth to solve the problem.

    It must be about time a flow chart was done to work through different issues.
    Yes I know every case is different but between us all there must be a checklist of things to do from the simple (disconnect the TPS) to the difficult/ cost money fixes. It would make an excellent sticky for sure.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: 06 inconsistent starting when warm / hot

    by Back2-2 » Sun Sep 30, 2018 7:00 pm

    You take the needle out and try and start the bike - guess what it starts just fine. The needle and and the main jet which is what the needle goes down into make absolutely zero difference with the starting of an engine.
    I've been doing this for a while... =DD
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: 06 inconsistent starting when warm / hot

    by JimDirt » Sun Sep 30, 2018 11:31 pm

    I agree with you on the point of it has nothing to do with "starting" Neil , what i am getting at is once the engine is running vacuum comes into play , the engine will suck up fuel from the bowl/main jet when the throttle would be opened , however with a worn needle jet (the emulsion tube) fuel is drawn up into the venturi and into the intake tract where you have now richened the mixture because of it , and since he was riding , and using the throttle , the extra fuel will not let the engine idle down and increased RPM is the result , as he was describing , even with the throttle now closed , you are not adding air to the mixture because the slide is at the bottom , but the fuel is now bypassing what was not allowing fuel before without throttle input and will affect the RPM's.......not trying to argue or say your wrong , just stating that if you add more fuel and its tuned for x amount , your richening the circuit ............ I am far from a carb expert , but more fuel is more fuel and it will be noticed when he lets off the throttle and the bike will not idle down , then the next time it will (because of the worn needle jet **not the needle**), and if the idle was adjusted in between , then it will either die , or be idling too high , and be "inconsistent" as mentioned , since he is adjusting it to one mixture , then it bypasses and the mixture changes , and so does the idle speed ................................................... or not :mrgreen: .......................... :-~
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Back2-2
    Posts: 1148
    Joined: Tue Jan 04, 2011 3:31 pm

    Re: 06 inconsistent starting when warm / hot

    by Back2-2 » Mon Oct 01, 2018 5:57 am

    There is one thing that maybe we have over looked. If it is a bike with CA emissions there may be some going on there. Those bikes had a air / idle emissions valve and plumbing.
    If so there may be something going on or it may be perfectly normal to have the odd idle ?

    Just something to look into.
    Neil
    Black Hills of SD
    Life without Motorcycles would just be boring, really boring
    Honda 450X. Yamaha Tracer GT900. HD Fat Boy. Triumph Bonneville. Yamaha Majesty 400. Yamaha Grizzly. Yamaha Wolverine. Yamaha TW200
  • User avatar
    metal_jd
    Posts: 5
    Joined: Thu Aug 09, 2018 4:33 pm

    Re: 06 inconsistent starting when warm / hot

    by metal_jd » Mon Oct 01, 2018 7:39 am

    The trouble for Metal_jd is both Jim and Neil are both right, though have identified different causes.

    Metal_jd just work your way through the suggestions till you find the cause.
    You will find a lot of knowledge and experience on the forum and we all like to put forward our 2 cents worth to solve the problem.

    It must be about time a flow chart was done to work through different issues.
    Yes I know every case is different but between us all there must be a checklist of things to do from the simple (disconnect the TPS) to the difficult/ cost money fixes. It would make an excellent sticky for sure.
    I have a flow / change chart started. And will update once I can get to it the fixes. Thank you all..

Who is online

Users browsing this forum: No registered users and 3 guests